The position of hydroxyl groups in organic-inorganic hybrid gate dielectrics was varied by altering the processing conditions and its effect on the organic thin film transistor (OTFT) was investigated. Although the hysteresis in OTFTs depends on both the hydroxyl groups on the surface and in the bulk of the gate dielectric, the hydroxyl groups on the surface had a greater effect on the OTFT performance. The reduced hysteresis was achieved by the elimination of the hydroxyl groups on the surface by hexamethyldisilazane surface treatment. (c) 2007 The Electrochemical Society. All rights reserved.